JPH09227192A - Concrete composition and concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a concrete composition having a small degree of slump loss by compounding a concrete composition containing fly ash with a reaction product of a copolymer of a specific polyoxyalkylene derivative and maleic anhydride, with a specific polyoxyalkylene derivative. SOLUTION: This concrete composition is obtained by compounding 1m<3> of a concrete composition mainly containing cement, water, fine aggregate and coarse aggregate with 50-300kg of fly ash and 0.1-10kg of the following additive. Additive: a reaction product obtained by the esterification reaction of a copolymer of a polyoxyalkylene derivative expressed by the formula R<1> O (A<1> O)n R<2> [R<1> is a 2-5C alkenyl; A<1> O is a 2-4C oxyalkylene; (n)=5-300; R<2> is a 1-8C hydrocarbon] and maleic anhydride, with a polyoxyalkylene derivative expressed by the formula R<3> O(R<2> O)m H [R<3> is a 1-8C hydrocarbon; R<2> O is a 2-4C oxyalkylene; (m)=1-200], or its salt.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a concrete composition and concrete. More specifically, the present invention relates to a concrete composition having excellent slump loss prevention property, high strength, and fly ash, and the concrete thereof.

[0002]

2. Description of the Related Art Concrete has the characteristics of high strength, freedom of shaping, excellent fire resistance, corrosion resistance, etc. In addition, it can be mass-produced, is cheap and easy to use, and is easy to use. Since it has many excellent features as a product such as, there is currently no construction material superior to this, and it is used in large quantities. In recent years, with the increase in the thickness and size of concrete structures, there has been an increasing demand for higher strength of concrete. In order to increase the strength of concrete, it is necessary to increase the hydraulic components such as cement in the concrete composition and decrease the water content, but since the viscosity after kneading the concrete composition increases, a water reducing agent, etc. Additives are needed. Therefore, a water reducing agent containing a small amount of water is desired. Furthermore, with the development of highly fluidized concrete, the performance requirements for water reducing agents have become even higher. As the water reducing agent, a naphthalene sulfonic acid formaldehyde condensate salt, a melamine sulfonic acid formaldehyde condensate salt, a lignin sulfonic acid salt, a polycarboxylic acid compound, or the like is used. The naphthalene sulfonic acid formaldehyde condensate salt and the melamine sulfonic acid formaldehyde condensate salt have a large slump loss, and the water reducing property cannot be said to be sufficient.
Lignin sulphonate has insufficient water reduction. Therefore, a polycarboxylic acid type water reducing agent is often used.

Usually, in 1 m ^{3 of} the concrete composition,
The component (A) cement is 200 to 600 kg, the component (B) water is 100 to 185 kg, the component (C) fine aggregate is 400 to 1200 kg, and the component (D) coarse aggregate is 400.
~ 1200 kg is contained as the main component. As one of the reuses of industrial waste, fly ash generated from a coal-fired power plant etc. is used as a part of these concrete compositions. (For example, "Hyperformance Concrete" by Gidoudou Publishing, Okamura, Maeda, Ozawa 50-
However, the amount used is only a part of the generated fly ash, and more use is desired. In addition, since activated carbon is contained in fly ash, the effect of a conventional admixture such as a water reducing agent may be reduced. When fly ash is used as a part of the concrete composition, even when using the above-mentioned polycarboxylic acid-based water reducing agent, there is a drawback that the slump loss becomes large, which is sufficient use of fly ash. Has not become one of the causes. Therefore, there is a demand for a concrete composition that does not increase the slump loss even when a large amount of fly ash is mixed and that maintains high strength.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a concrete composition containing a large amount of fly ash and having a small slump loss, and a high-strength concrete obtained by curing the concrete composition.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that fly ash, a specific polyoxyalkylene derivative and maleic anhydride are treated by a specific method. It was found that a concrete composition containing a copolymerized copolymer and a reaction product of a specific polyoxyalkylene derivative gives a concrete having a small slump loss and high strength, and completed the present invention. It was That is, the present invention provides (1) a concrete composition containing (A) cement, (B) water, (C) fine aggregate and (D) coarse aggregate as main components, in 1 m ³ of the concrete composition, (E) 50 to 300 kg of fly ash, and (F) the following general formula (1), R ¹ O (A ¹ O) _n R ² (1) (wherein R ¹ is an alkenyl group having 2 to 5 carbon atoms, A ¹ O is an oxyalkylene group having 2 to 4 carbon atoms, n = 5 to 300,
R ² represents a hydrocarbon group having 1 to 8 carbon atoms. Further, 50 mol% or more of the oxyalkylene group is an oxyethylene group. ) A polyoxyalkylene derivative and a maleic anhydride copolymer, and the following general formula (2), R ³ O (A ² O) _m H (2) (wherein R ³ has 1 to 8 carbon atoms). A hydrocarbon group, A ² O is an oxyalkylene group having 2 to 4 carbon atoms, and polyoxyalkylene derivative represented by m = 1 to 200) and the number of maleic anhydride residues in the copolymer and the general formula The ratio of the number of hydroxyl groups in the polyoxyalkylene derivative of (2) is 1: 1.
The concrete composition is characterized by containing 0.1 kg to 10 kg of an additive consisting of a reaction product esterified at 5-1: 0.1 or a salt thereof. (2) A concrete obtained by curing the concrete composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The concrete composition of the present invention is
Concrete that does not harden yet, JISA1138
It has a property that it can be mixed according to "how to make concrete in a test room" and can be analyzed according to JIS A1112 "Method for washing analysis test of concrete not yet hardened".

In 1 m ³ of the concrete composition of the present invention, the component (A) cement is 200 to 500 kg, the component (B) water is 100 to 185 kg, and the component (C) fine aggregate is 400 to 400 kg. 1200 kg, 400 for coarse aggregate of component (D)
~ 1200 kg is contained as a main component. Examples of the component (A) cement used in the present invention include Portland cement, and a composition obtained by mixing Portland cement with blast furnace slag, limestone powder, silica powder, silica fume and the like can also be used. it can. In the composition of the present invention, concrete composition 1
200 to 500 kg of cement is mixed in m ³ . 200 kg of cement in 1 m ^{3 of} concrete composition
If it is less than the above range, the strength of the concrete after curing becomes insufficient. The amount of cement in 1 m ^{3 of} concrete composition is 5
If it exceeds 00 kg, the heat generated by the hardening of the cement increases, the drying shrinkage increases, and cracks easily occur.

In the composition of the present invention, the water of the component (B) is 100 to 185 kg in 1 m ^{3 of} the concrete composition.
Is blended. If the amount of water in 1 m ^{3 of the} concrete composition is less than 100 kg, it may be difficult to mix the concrete or the flow may decrease. When the amount of water in 1 m ^{3 of the} concrete composition exceeds 185 kg, the strength of the concrete becomes insufficient. In the present invention, the amount of water in the concrete composition is particularly important, so if the fine aggregate or coarse aggregate to be blended is not in a surface-saturated state of water saturation, quantify the water content and actually blend. A correction must be made to the amount of water.

The fine aggregate of the component (C) used in the present invention is an aggregate which passes through a 10 mm mesh sieve defined by JIS A0203 and passes through a 5 mm mesh sieve in an amount of 85% or more by mass. Aggregates include river sand, land sand, mountain sand, sea sand, and crushed sand. In the composition of the present invention, 400 to 1200 kg of fine aggregate is mixed in 1 m ^{3 of} concrete. The amount of fine aggregate in 1 m ^{3 of the} concrete composition is 40
If it is less than 0 kg, the coarse aggregate easily separates, and the workability such as transportation, driving, compaction, and finishing is deteriorated. The amount of fine aggregate in 1 m ^{3 of the} concrete composition is 120
When it exceeds 0 kg, workability is impaired again.

The coarse aggregate of the component (D) used in the present invention is an aggregate that stays in a 5 mm mesh sieve defined by JIS A0203 in an amount of 85% or more by mass. Such aggregate includes river gravel. , Land gravel, mountain gravel, crushed stone, etc. In the composition of the present invention, 400 to 1200 kg of coarse aggregate is mixed in 1 m ^{3 of} the concrete composition. If the amount of coarse aggregate in 1 m ^{3 of the} concrete composition is less than 400 kg, the strength of the concrete may decrease. If the amount of coarse aggregate in 1 m ^{3 of the} concrete composition exceeds 1200 kg, the workability is impaired. In the composition of the present invention, the weights of the fine aggregate and the coarse aggregate are weights in a surface-dried saturated state. It is necessary to select the types and amounts of the fine aggregate and the coarse aggregate to be added to the concrete composition in consideration of an appropriate balance such as economical efficiency, heat generation during curing, drying shrinkage, and aggregate separation.

The component (E) fly ash used in the composition of the present invention generally includes fly ash collected from a flue gas of a pulverized coal combustion boiler by a dust collector at a thermal power plant or the like. . Usually, the fly ash has a Blaine value (specific surface area) of 2500 to 10000 cm ² / g, and can be appropriately selected and used when the present invention is used. In the composition of the present invention, 50 to 300 kg of fly ash is mixed in 1 m ^{3 of} the concrete composition. When the amount of fly ash in 1 m ^{3 of the} concrete composition is less than 50 kg, the purpose of the present invention is not met and the workability is deteriorated. When the amount of fly ash in 1 m ^{3 of the} concrete composition exceeds 300 kg, the initial strength of the concrete becomes insufficient.

In the general formula (1), R ¹ has 2 to 2 carbon atoms.
5 is an alkenyl group, and examples of such an alkenyl group include a vinyl group, an allyl group, a methallyl group, and 3-
Examples thereof include butenyl group, 4-pentenyl group, 3-methyl-3-butenyl group and the like. When the alkenyl group represented by R ¹ has more than 5 carbon atoms, the copolymer obtained has insufficient hydrophilicity.

In the general formula (1), R ² has 1 to 1 carbon atoms.
8 is a hydrocarbon group, and examples of such a hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, an amyl group, an isoamyl group, and a hexyl group. And saturated hydrocarbon groups such as heptyl group and octyl group; cyclic hydrocarbon groups such as cyclohexyl group, phenyl group, benzyl group, tolyl group and phenethyl group. When the hydrocarbon group represented by R ² has more than 8 carbon atoms, the resulting copolymer has insufficient hydrophilicity.

In the general formula (1), A ¹ O has 2 carbon atoms.
To oxyalkylene groups of 4 to 4, and examples of such an oxyalkylene group include an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxytetramethylene group. When the oxyalkylene group represented by A ¹ O is an oxymethylene group, the compound represented by the general formula (1) is unstable and produces harmful formaldehyde by decomposition. When the number of carbon atoms of the oxyalkylene group represented by A ¹ O exceeds 4, the hydrophilicity of the compound represented by the general formula (1) becomes insufficient. In the compound represented by the general formula (1) used in the composition of the present invention, 50 mol% of the oxyalkylene group
The above is an oxyethylene group. When the oxyethylene group in the oxyalkylene group is less than 50 mol%, the water solubility becomes insufficient and the performance as a water reducing agent deteriorates. In the general formula (1), the value of n is 5 to 300. If the value of n is less than 5, the setting delay becomes large, and the value of n is 30.
If it exceeds 0, the viscosity becomes high and the production becomes difficult.

The copolymer of the polyoxyalkylene derivative represented by the general formula (1) and maleic anhydride is obtained by combining the polyoxyalkylene derivative of the general formula (1) and maleic anhydride with a peroxide initiator, It can be easily obtained by copolymerizing using an azo initiator or the like by a known method. At that time, a solvent such as benzene, toluene, and xylene can be used. Further, a copolymer obtained by adding another copolymerizable monomer such as styrene or vinyl acetate at the time of copolymerization can also be used in the composition of the present invention.

The reaction molar ratio of the copolymerization of the polyoxyalkylene derivative represented by the general formula (1) and maleic anhydride is preferably 3: 7 to 7: 3, and particularly preferably about 1: 1. When the polyoxyalkylene derivative represented by the general formula (1) is copolymerized with maleic anhydride, the water content in the system should be 1% by weight or less of the total amount of the polyoxyalkylene derivative and maleic anhydride. preferable. If the water content in the system is more than 1% by weight of the total amount of the polyoxyalkylene derivative and maleic anhydride, the reactivity is poor and the molecular weight of the copolymer is unlikely to increase, and the copolymer and the general formula (2) Becomes less reactive.

In the general formula (2), R ³ has 1 to 1 carbon atoms.
8 is a hydrocarbon group, and examples of such a hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, an amyl group, an isoamyl group, and a hexyl group. Saturated hydrocarbon groups such as heptyl group and octyl group; allyl group, butenyl group,
Unsaturated hydrocarbon groups such as a pentenyl group; and cyclic hydrocarbon groups such as a cyclohexyl group, a phenyl group, a benzyl group, a tolyl group, and a phenethyl group. R ³
When the number of carbon atoms of the hydrocarbon group represented by is more than 8, the hydrophilicity of the compound represented by the general formula (1) becomes insufficient. In the general formula (2), A ² O is an oxyalkylene group having 2 to 4 carbon atoms, and examples of such an oxyalkylene group are the same as the specific examples shown for A ¹ O above. When the number of carbon atoms of the oxyalkylene group represented by A ² O exceeds 4, the copolymer of the polyoxyalkylene derivative represented by the general formula (1) and maleic anhydride and the polyoxyalkylene represented by the general formula (2) The foaming property of the additive, which is a reaction product with the derivative, is increased. In the general formula (2), the value of m is 1 to 200. m is 20
If it exceeds 0, the viscosity becomes high and it becomes difficult to handle.

The reaction product of the copolymer of the polyoxyalkylene derivative represented by the general formula (1) and maleic anhydride, the reaction product of the polyoxyalkylene derivative represented by the general formula (2) and the general formula (2) is A copolymer of the polyoxyalkylene derivative represented by the general formula (1) and maleic anhydride and the polyoxyalkylene derivative represented by the general formula (2) are mixed without heating with a catalyst or in the presence of a catalyst. It can be easily obtained by mixing at room temperature or under heating. Examples of the catalyst include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium methylate, ammonia, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine and the like.

The salt of the reaction product of the copolymer of the polyoxyalkylene derivative represented by the general formula (1) and maleic anhydride and the polyoxyalkylene derivative represented by the general formula (2) is, for example, water. Alkali metal salts obtained by neutralizing with sodium oxide, potassium hydroxide, etc .; Alkaline earth metal salts obtained by neutralizing with calcium hydroxide, magnesium hydroxide, etc .; Monoethanolamine, diethanolamine, triethanolamine Examples thereof include amine salts obtained by neutralization with ammonia; ammonium salts obtained by neutralization with ammonia. In the composition of the present invention, a reaction product of a copolymer of a polyoxyalkylene derivative represented by the general formula (1) and maleic anhydride and a polyoxyalkylene derivative represented by the general formula (2) or a salt thereof. The additive consisting of 0.1 is contained in 1 m ^{3 of} the concrete composition.
-10kg, preferably 0.4-5kg. The content of the additive in 0.1 m ^{3 of the} concrete composition is 0.1
If it is less than kg, a sufficient slump loss preventing effect cannot be obtained. Even if the compounding amount of the additive in 1 m ^{3 of the} concrete composition exceeds 10 kg, the effect corresponding to the increase of the compounding amount cannot be obtained.

In the concrete composition of the present invention, other components such as a naphthalene sulfonic acid formalin condensate salt, a melamine sulfonic acid formaldehyde condensate salt, a polycarboxylic acid type compound, etc. may be used as long as the performance of the composition of the present invention is not impaired. Additives, or other defoaming agents, air entraining agents, rust preventives, setting accelerators, setting retarders and the like can be added.

The concrete composition of the present invention can be mixed using a known mixer such as a batch mixer or a continuous mixer, but it is preferable to use a batch mixer such as a biaxial forced mixing mixer or a tilting mixer. You can The concrete composition of the present invention can be used as fresh concrete, concrete for secondary products, and the like. The concrete composition of the present invention can be used for various fluidity concretes such as super-hard concrete and high-fluidity concrete, but is particularly excellent for high-fluidity concrete having a slump flow of 40 cm or more.

[0022]

The concrete composition of the present invention has a small slump loss even when a large amount of fly ash is mixed,
Workability is good. Further, the hardened concrete of the present invention has high compressive strength.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The numerical values in the table are the values corrected by measuring the water content of fine aggregate and coarse aggregate. The slump flow and compressive strength were measured by the following methods. (1) Slump flow value: According to JIS A1101, a slump cone is packed with concrete, then the slump cone is gently pulled up vertically and left standing until the concrete flow stops. After that, the diameter of the spread of concrete is measured at two points, which are the maximum value and the direction perpendicular to this, and the average value is taken as the slump flow value. The symbol (-) in the table indicates that the slump flow value was so bad that the test was stopped halfway. <Measurement conditions of slump flow value> Each component in the table was placed in a forced kneading mixer, kneaded for 3 minutes, taken out, and immediately after mixing, the slump flow was measured. Transfer to a tilting mixer, mix at 2 revolutions per minute, and after 30 minutes, 60 minutes, 90
The slump flow after the minute was measured. (2) Compressive strength: 2 after molding according to JIS A1108
The 8 day concrete was measured.

Example 1 315 kg of Portland cement as component (A), 170 kg of water as component (B), sand 79 as component (C)
0 kg, 894 kg of gravel as component (D), 135 kg of fly ash of component (E) and 1.80 kg of additive 1 of Table 2 as component (F) are taken in a forced kneading mixer and mixed for 3 minutes to obtain a concrete composition. It was

Examples 2 to 20 and Comparative Examples 1 to 14 As in Example 1, the copolymers shown in Table 1 were used as raw materials and the component (F) of the present invention shown in Table 2 was used. Using the additives 1 to 8 or the other additives a to d shown in Table 3, the concrete composition was compounded with the composition shown in Tables 4 and 2 and 5 and 1 and 2. . The slump flow value and the compressive strength were measured, and the results are shown in Tables 4 and 2 and 5 and 1 and 2, respectively.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

[0031]

[Table 6]

[0032]

[Table 7]

From the above results, the concrete composition of the present invention has less slump loss and has sufficient fluidity than the concrete compositions of Comparative Examples, and the concrete after curing has sufficient and compressive strength. I know I have it.
That is, Example 1 using the additive used in the present invention
9 and 10 to 18 have a high slump flow value, whereas the copolymers of general formula (1) and maleic acid are only general formula (2).
Comparative Examples 1 and 6 using an additive which is not a reaction product with
Has a low slump flow value over time, and
In Comparative Examples 2 and 7 using the additive having a hydroxyl group at the terminal of the general formula (1), the slump flow value becomes lower with time. Furthermore, the slump flow value is also low in Comparative Examples 3 and 8 in which a polycarboxylic acid-based compound which is a conventional technique is used as an additive, and Comparative Examples 4 and 9 in which sodium salt of naphthalenesulfonic acid formaldehyde condensate is used as an additive. . Further, it can be seen that Comparative Examples 5 and 10 in which no additive is used have a low slump flow value and lose fluidity in the middle.

Claims (2)

[Claims] 1. A concrete composition comprising (A) cement, (B) water, (C) fine aggregate and (D) coarse aggregate as main components, wherein (E) fly is added to 1 m ³ of the concrete composition. 50 to 300 kg of ash, and (F) the following general formula (1), R ¹ O (A ¹ O) _n R ² (1) (wherein R ¹ is an alkenyl group having 2 to 5 carbon atoms, A ¹ O is An oxyalkylene group having 2 to 4 carbon atoms, n = 5 to 300,
R ² represents a hydrocarbon group having 1 to 8 carbon atoms. Further, 50 mol% or more of the oxyalkylene group is an oxyethylene group. ) A polyoxyalkylene derivative and a maleic anhydride copolymer, and the following general formula (2), R ³ O (A ² O) _m H (2) (wherein R ³ has 1 to 8 carbon atoms). A hydrocarbon group, A ² O is an oxyalkylene group having 2 to 4 carbon atoms, and polyoxyalkylene derivative represented by m = 1 to 200) and the number of maleic anhydride residues in the copolymer and the general formula The ratio of the number of hydroxyl groups in the polyoxyalkylene derivative of (2) is 1: 1.
A concrete composition comprising 0.1 to 10 kg of an additive consisting of a reaction product esterified at a ratio of 5 to 1: 0.1 or a salt thereof. 2. A concrete obtained by curing the concrete composition according to claim 1.